A sintered alloy member, such as a cam lobe of a camshaft, is subjected in service to a high plane pressure and therefore is required to be highly abrasion-resistant. For the purpose of increasing the anti-wear property of the sintered alloy member, B, Cu, Nb, V and the like are added to produce a hard precipitation dispersed in the matrix of the alloy member. Otherwise, Mo, Ni and the like are added to harden the matrix. However, this leads to a problem that the obtained anti-wear sintered alloy member readily scuffs the opposing member under poor lubrication in the starting up period in which the oil film has not yet been sufficiently formed to cover the entire sliding surface. For protecting the opposing member against scuffing, it has been suggested to cover the sliding surface of the anti-wear sintered alloy member with a phosphatic film.
But, in the case of a member made of a material containing a relatively large amount of Cr and/or Ni, it is very difficult to form a sufficient film of phosphate over the sliding surface, resulting in the fact that the phosphatic treatment is ineffective in protecting the opposing member against scuffing.
The present invention is intended to resolve the problem as described above and provide an anti-wear sintered alloy member wherein the sliding surface is sufficiently coated by a phosphatic film, whereby the inventive member is superior in its anti-scuffing property.